Drive arrangement

ABSTRACT

A drive arrangement for a shaft, such as a shaft for driving a sectional door, roller shutter or the like, is in the form of a module, carried, in use, by the shaft and including a motor, a driven wheel fixed for rotation with the shaft and drivable, in use, by the motor, and clutch means and operable between the motor and the wheel. The module further includes brace means in the form of a limb attachable to a member which is fixed relative to the axis of the shaft, to brace the module against turning as the shaft is driven.

This is a national stage application filed under 35 USC 371 based onInternational Application No. PCT/GB2002/002095 filed May 7, 2002, andclaims priority under 35 USC 119 of United Kingdom Patent ApplicationNo. 0111252.3 filed May 9, 2001.

BACKGROUND OF THE INVENTION

The present invention relates to drive arrangements and in particular,but not exclusively, to drive arrangements for driving shafts ofelectrically operated doors, shutters and the like.

Many doors, such as up-and-over garage doors, roller shutter doors andthe like are provided with motors for driving the doors to open or dose.In previous proposals, the motor may be mounted on a framework or doorsurround but previous proposals have proved bulky or difficult and timeconsuming to fit, particularly when fitted to existing door systems inplace of other motor arrangements.

SUMMARY OF THE INVENTION

The present invention provides a drive arrangement for a shaft, thearrangement having a module which is carried, in use, by the shaft andincludes a motor, a driven wheel fixed, in use, for rotation with theshaft and drivable, in use, by the motor, and clutch means operablebetween the motor and the wheel, the module further comprising bracemeans attachable to a member which is fixed relative to the shaft axis,to brace the module against turning as the shaft is driven.

The driven wheel is preferably fitted around the shaft and keyedthereto.

The module may comprise a base assembly, and a bearing assembly by whichthe driven wheel is mounted on the base assembly, whereby the module iscarried by the shaft by means of the driven wheel being fixed forrotation with the shaft.

Preferably the motor drives a drive wheel, and the module has a beltaround the drive wheel and the driven wheel. The clutch means preferablyserves to movably mount the motor and drive wheel relative to the drivenwheel, so that the belt can be releasably engaged with the wheels bymeans of relative movement between the wheels. The module may have abase assembly carried by the shaft, and a carriage assembly carried bythe base assembly and movable relative thereto. The base assembly mayhave a first member fixed relative to the rotation axis of the drivenwheel, the carriage assembly having a second member fixed relative tothe rotation axis of the drive wheel, the first and second members beingmovable relative to one another. The first and second members may beplate members.

The module may include pillar members fixed relative to the first orsecond member, and slots formed in the second or first member,respectively, to allow relative movement of the first and secondmembers.

The arrangement may further comprise a clutch actuating means by whichthe clutch may be engaged and disengaged. The actuating means mayinclude a cable. The actuating means may include tension means operable,in use, to apply releasable tension to the cable, to cause the cable topull the clutch means to the engaged condition. The actuating means mayinclude an over-centre catch mechanism. The actuating means may bemounted at a position which is fixed relative to the axis of the shaft.

The brace means may be a limb carried by the module and extending to adistal end at which the limb may be attached to a fixed member, asaforesaid.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention will now be described in more detail, byway of example only, and with reference to the accompanying drawings, inwhich:

FIG. 1 is a front perspective view of an embodiment of the presentinvention installed for driving a shaft;

FIG. 2 is a rear perspective view of the arrangement of FIG. 1;

FIG. 3 is a front elevation of the arrangement of FIGS. 1 and 2;

FIG. 4 is an end elevation of the arrangement; and

FIG. 5 is a section of the arrangement, along the line V-V of FIG. 3.

DETAILED DESCRIPTION

FIG. 1 shows a drive arrangement 10 for a shaft 12, such as a shaft fordriving a sectional door, roller shutter or the like. The arrangement 10is in the form of a module, carried, in use, by the shaft 12 andincluding a motor 14, a driven wheel 16 fixed for rotation with theshaft 12 and drivable, in use, by the motor 14, and clutch meansindicated generally at 18 and operable between the motor 14 and thewheel 16. The module further includes brace means 20 (FIG. 2) in theform of a limb attachable to a member which is fixed relative to theaxis of the shaft 12, to brace the module against turning as the shaft12 is driven.

In more detail, the module 10 has a back plate 22 attached by means oftwo upper pillars 24 and a lower pillar 26 to a front plate 28. Thedriven wheel 16 is located between the plates 22, 28 and mounted to themby bearings 30 (FIG. 5). The wheel 16 is fitted around the shaft 12. Theshaft 12 and wheel 16 both have corresponding keyways to allow theintroduction of a loose key 32 into both keyways, so that the wheel 16is fixed for rotation with the shaft 12. Drive to the wheel 16 isprovided through a belt 34 from a drive wheel 36. The drive wheel 36 isdriven by the motor 14 through a gearbox 38 which has an output shaft 40on which the wheel 36 is mounted.

Consequently, operation of the motor 14 acts, through the gearbox 38 toturn the shaft 40 and thus the wheel 36. If the belt 34 is engaged withthe wheel 36 and also with the wheel 16, this drive is passed to thewheel 16 and thus to the shaft 12, thereby driving the door, shutteretc. However, the engagement of the belt 34 with the wheels 16, 36 isreleasable, as can now be described.

In addition to the back and front plates 22, 28, which are fixed inposition relative to the rotation axis of the shaft 12, the arrangement10 further includes a slider plate 42 which carries the gearbox 38. Themotor 14 may be mounted directly on the slider plate 42, or on thegearbox 38. However, the motor 14 and gearbox 38, and thus the outputshaft 40 and drive wheel 36 are fixed to the slider plate 42.

The slider plate 42 has upper slots 44 to receive the upper pillars 24,and a lower slot 46 to receive the lower pillar 26. The fit of thepillars 24, 26 in the slots 44, 46 allows the plate 42 to slide to alimited extent, relative to the plates 22, 28. A further slot 48 may beprovided in the back plate 22 to receive the free end of the outputshaft 40. The slider plate 42 thus forms a carriage by which the motor14 and gearbox 38 move relative to the back plate 22 and front plate 28.

In consequence, the separation of the rotation axis of the wheels 16, 36can be changed by sliding the plate 42 relative to the plates 22, 28. Ifthe wheel 36 is moved away from the wheel 16, the belt 34 will tend totighten until the belt 34 is driven by the wheel 36, and conveys thedrive to the wheel 16. However, if the wheel 36 is moved towards thewheel 16, or is released to be free to move, engagement between the belt34 and the wheels 16, 36 will be lost, and drive will not be conveyed asjust described. The sliding motion of the plate 42 thus provides thearrangement 10 with a form of clutch between the motor 14 and the wheel16.

In normal use, it is envisaged that the clutch will remain engaged, withthe belt 24 engaging the wheels 16, 36. To this end, a clutch cable 50is secured at one end to the plate 42 and provided, at its other end,with an arrangement (not shown) for pulling the cable 50 in order topull the wheel 36 away from the wheel 16 and tighten the belt 34. Thepulling arrangement may be an over-centre catch mechanism mounted at aconvenient position, such as on the door frame or adjacent wall. It isenvisaged that the cable 50 would be continuously pulled in this manner,during normal use, so that the belt 34 and wheels 16, 36 are normallyengaged. Rotation of the shaft 12 (including the direction of rotation)can therefore be controlled by appropriate control of the motor 14.However, in the event that motor control is to be overridden (such as inthe case of an emergency, fault in the motor or drive, or obstruction ofthe door being driven), tension on the cable 50 would be released,allowing the plate 42 to move up, releasing the engagement between thebelt 34 and the wheels 16, 36.

In addition to the cable 50, the drawings show an alternative overridemechanism which includes an over-centre catch 52 mounted on the frontplate 28, and a claw 54 reaching above the front plate 28 and over theedge of the slider plate 42. When the catch 52 is engaged as shown inFIG. 1, the claw 54 pulls the plate 42 down, to engage the belt 34 withthe wheels 16, 36, as has been described. Alternatively, the catch 52can be released by pulling the tab 56 away from the plate 28, thusreleasing the pull of the claw 54 on the slider plate 42 and disengagingthe belt 34, as has been described. It is envisaged that the claw 54 andcable 50 would not both be provided in a single installation, becauseboth would need to be released in order to override the motor 14, but itis convenient to illustrate both alternatives in a single drawing. It isenvisaged that tension on the cable 50 may be controlled by anover-centre catch of the type illustrated at 52.

It is envisaged that the belt 34 may be a strongly resilient materialsuch as a synthetic plastic or rubber material, preferably having aplurality of V-shaped ribs along its length, and fitting intocorresponding V-shaped circumferential grooves in the wheels 16, 36, ascan be seen in FIG. 5. Alternatively, a toothed belt could be used. Achain could be used with toothed wheels, but it is envisaged that moreelaborate arrangements would then be required to ensure that the driveis fully disengaged by the operation of the clutch. Further alternativearrangements could be envisaged.

A fixing screw or other arrangement is preferably provided to preventmovement of the arrangement 10 axially along the shaft 12.

It will be understood from the above description and the accompanyingdrawings that when the motor 14 is in use, the arrangement 10 will seekto apply torque to the shaft 12 in order to move the door, shutterarrangement etc. The reaction to this torque will tend to turn thearrangement 10 about the axis of the shaft 12. This torque is borne bythe limb 20. The limb 20 is a rigid arm fixed at one end to the backplate 22, and extends away to a distal end 58 at which the limb 20carries a plate 60. The plate 60 has bolt apertures 62 by which theplate 60 can be secured to a convenient member fixed relative to theaxis of the shaft 12. The arrangement is then braced against turning asthe shaft 12 is driven. The limb 20 is preferably adjustable in length,to assist in readily fixing in this manner, and may be attached to theplate 22 in a manner which readily allows for changes in the angle atwhich the limb 20 extends away from the back plate 22.

The arrangement described above can readily be installed for driving anexisting shaft 12, in the following manner. First, the module, which isself-contained, is offered to the end of the shaft 12 to fit the wheel16 over the shaft end, and may be secured against further axialmovement, as described above. The weight of the module is then supportedby the shaft 12. The limb 20 is then secured to an appropriate member,such as a part of the door surround, or a convenient nearby wall. Thisis the only external fixing required if the catch 52 is being used. Ifthe cable 50 is to be used, an appropriate arrangement must be made atthe other end of the cable 50. The arrangement 10 is then in conditionfor use, as described above.

It will therefore be understood that installation is relatively simplein comparison with many prior proposals, and in particular, can requireonly a single member (the plate 60) to be bolted to a fixed structure.

It will be apparent from the above description that many variations andmodifications can be made to the apparatus described above, withoutdeparting from the scope of the present invention. In particular, manydifferent materials and many different shapes, sizes and relative shapesand sizes can be used for the various components. The cable 50 could,alternatively, be a chain or other flexible elongate member able tocontrol the clutch. The term “cable” should therefore be interpreted asextending to cover these alternatives.

Whilst endeavouring in the foregoing specification to draw attention tothose features of the invention believed to be of particular importanceit should be understood that the Applicant claims protection in respectof any patentable feature or combination of features hereinbeforereferred to and/or shown in the drawings whether or not particularemphasis has been placed thereon.

1. A drive arrangement, the arrangement having a module which includes amotor, a driven wheel mounted, in use, for rotation within the moduleand drivable, in use, by the motor, and clutch means operable betweenthe motor and the wheel, and wherein the motor drives a drive wheel, andthe module has a belt around the drive wheel and the driven wheel, andthe clutch means serves to movably mount the motor and the drive wheelrelative to the driven wheel, so that the drive wheel is movablerelative to the driven wheel to increase the separation of the rotationaxes of the said wheels, and to releasably tighten the belt until thebelt tightens to convey drive from the drive wheel to the driven wheel,and wherein the drive wheel is releasable to decrease the separation ofthe rotation axes of the said wheels and to disengage drive from thedrive wheel to the driven wheel, through the belt, the module furthercomprising brace means, wherein the module is installable as a singleunit to a target installation having a shaft to be driven by thearrangement, and is removable as a single unit from the targetinstallation, the module being installable to drivingly engage the shaftof the target installation, and wherein the brace means is attachable,when the module is installed, to a member which is fixed relative to therotation axis of the driven wheel, to brace the module against turningas the driven wheel is driving the shaft, during use, and wherein themodule comprises a base assembly, and a bearing assembly by which thedriven wheel is mounted on the base assembly, whereby the module iscarried by the shaft by means of the driven wheel being fixed forrotation with the shaft.
 2. An arrangement according to claim 1 in whichthe driven wheel is fitted around the shaft and keyed thereto.
 3. Anarrangement according to claim 1 in which the base assembly is carriedby the shaft, and the module has a carriage assembly carried by the baseassembly and movable relative thereto.
 4. An arrangement according toclaim 3 in which the base assembly has a first member fixed relative tothe rotation axis of the driven wheel, the carriage assembly having asecond member fixed relative to the rotation axis of the drive wheel,the first and second members being movable relative to one another. 5.An arrangement according to claim 4 in which the first and secondmembers are plate members.
 6. An arrangement according to claim 4 inwhich the module includes pillar members fixed relative to the first orsecond member, and slots formed in the second or first member,respectively, to allow relative movement of the first and secondmembers.
 7. An arrangement according to claim 1 in which the arrangementfurther comprises a clutch actuating means by which the clutch may beengaged and disengaged.
 8. An arrangement according to claim 7 in whichthe actuating means includes a cable.
 9. An arrangement according toclaim 8 in which the actuating means includes tension means operable, inuse, to apply releasable tension to the cable, to cause the cable topull the clutch means to the engaged condition.
 10. An arrangementaccording to claim 7 in which the actuating means includes anover-center catch mechanism.
 11. An arrangement according to claim 7 inwhich the actuating means is mounted at a position which is fixedrelative to the axis of the shaft.
 12. An arrangement according to claim1 in which the brace means is a limb carried by the module and extendingto a distal end at which the limb may be attached to the fixed member,as aforesaid.